Driving gear



DRIVING GEAR Aug. 7, 11923. l 'y www@ A. PETERSON I I M lll) Patentedfitug. i?, llt-i923..

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`tltlllD PETERSON, OF TRENTON, NEW' JERSEY, ASEGNVOE T0 LAVAL STEAM:

TURBINE COMPANSYI, O?? TRENTON, NE`W JERSEY, A

Jnnsnr. y

CR-POEATON OF NEVI DRIVNG GEAR.

application sied July aa, 192i. serial ne. asesor.

To all 'whomv it may concern.' Y Be it known that ll, Alwin ljfnfrnnson,a citizen of the United States, residing at rlrenton, county ot Mercer,and State oiI New Jersey, have invented a new and .useful lmprovement inDriving Gear, of which the face, heavy duty pinions, such as high speedgear reduction pinions in large power plants.

in pinions of this character, it is very essential that the load to thepinion should be uniformly distributed without distortion ot the pinion,as such distortion will cause uneven contact betweenthe teeth on thedriving pinion-and the teeth on the driven gear, and will also cause avariation in contact d ue toiload conditions.

rlhe object of my invention is to providel a pinion in which thisdistortion will be materially reduced. l yaccomplish this by providing apinion which is so constructed that it acts when under a load in ,amanner substantially the `same as a pinion under a load which is drivenfrom bothjends with substantially one-halt the power being transmittedthrough'each end of the pinion. ln designing a pinion, l irst calculatethe distortion due to the twist caused by the load on the pinion, andthen provide a pinion having a twist relative to the gear equalsubstantially to one-half the twist to which the pinion is subjectedwhen under substantially the maximum load, and in the reverse directionto the twist caused by the load. The pinion is relatively'twisted insuch a manner that the faces ot the engaging teeth of the pinion at theend opposite the driven end of the pinion are in engagement with theteeth of the driven gear, while the faces of the teeth at the driven endof the pinion are clear or substantially tree of the teeth of the drivengear when the pinion is running light or without load.

The precise nature of my invention will be best understood by referenceto the accompanying drawings, which will now be and is as followsdescribed, it being premised, however, that changes may be madeA in theform of the structure without departing from the spirit and scope of myinvention as defined in the appended claims.

F ig. l of the drawings is a diagram of a herring-bone pinion drivenfrom one end, together with a graduated curve chart illustrating thedistortion of the pinion at dir"- ferentl points, and a diagram of asimilar pinion to illustrate the eliect it driven from both ends. Fig.2' is a longitudinal sectional `view through one form of pinionconstructedin accordance with my invention, and a portionv oi" a geardriven thereby.

ln calculating the amount of `distortion due to twist, it is assumedthat the torque diminishes gradually from the coupling end of the piniontowards the, tree end and that the pinion is tree to move endwise sothat each helix takes its share of the load. The formula for calculatingthe distortion due totwist is obtained from lluttesl'lngineerslocketBook, Vol. l, pages 570, 571

32 Har zrelative angular displacement of two sections in inches at lradius and l apart (Zzdiameter of shaft inches.

m T A L and the `distortion of two sections dm .32 ttt o or thedistortion at any point y ITG- mls. 2

' los Taking as an example a i ting 3000 H P. at 3600 R. .M. of thefollowing dimensions- Pitch diameter 627.8.

,144.8 y. 104105 .i e In otherwords there would be an opening of Contactat-B on the-.right hand lielixof OOM-00022100067 vresulting in, heavyload at C and on the left hand helix there Y would be anopening ofContact. at' A ofV '.0002 resulting in heavy'load lat B on this helix.VQ. L :H

The curve P drawn up showsthe` distortion at different points of. thepinion.,.l 1.

Now, if it were possible to drive the pinion from both ends asy atP.with half the power going into each end, the distortionrdue to twistwill-beV diminished materially in the right handlhalf. .l y A f. VThefigures below will show this. We now have going into each end, and thelength subjected to twist is now 20250111@ ibs.

so that Y Q Y 20250 1e 17z J1 17 i2 10 w 7 8? 2* Accordingly the,ldistortion: inleachheliii will now be only .0002 as shown by curveV 0'compared'with .0006 before7 in the right handheliX or a reduction indistortion of one Y ends as the pinionl third. Y In the `vleft -handhelixV the amountof'distortion will. naturally be thesamezas before. Theresults from a pinion constructed in accordance Vwith.njiy invention, ifdriven from the right hand end,.will vbe substantially the same as apinion driven from both of Fig. l. Y The pinion illustrated in ,F ig. 2comprises a sleeve or hub 'g' having two sets of helical teeth zythereon7 a flange jat the driven end and a similar flange Vla .at theother end,

inion transmit- Y Passing through the hub g is a quill shaft f, havingan integral iiange m at one end, which is connected to a coupling'member n Yonrthe drive shaft o, and the flange j on the shaftby a pin p.g

1' is a iianged collar or connecting member secured to the other end ofthe quill shaft7 and is secured `to the flange k on the. huh

of the pinion by means of a pins..` 4The cob llar r is keyed to afrusto-conical seat on the quill shaft and is held to said seat by a nutt. .w a Lgearwheel havingV two sets of teeth which mesh with the teethon the pinion. Y x A In order to Ytransmit Vsubstantially .the same loadthrougheach end of thepinion.

I `first calculate the twist-caused by the load l to .be driven by thepinion, ythen lay- `out and f formf'the -holes inthe different membersfor the coupling pins7 `twist the shaft Vf andV couple. The; twistingofltheshaft tonthe proper l degree will t align; .Y the various holesfor the pins7 and' when coupled. `the. pinion will be. under.substantiallyl one-'half the Vtwistingstress to which theypinion issub.-

jected Vwhen' under itsA normal .load7 but which twist is inthe. reversedirection tothe twist caused by the load. VWhen the shaft Q is rotatedand the pinionis underthe normal load, .the effect will be Athesanie .as1i-f the pinion were drivenat 'bothzends with equal power. If desiredVthe twist caused. by theloadniay be'de'te1'n1inedV bytest7 and thepinionfand gear may then be made in accordancefwithsuch test.

The advantages of my invention vresult from` the provision of a. pinionandthe method of making a Avpinion having a twist thereinwhich,willcause the teeth on!V the oppositelends. thereof to Contact with theteeth onpthexgearwheel driven thereby .when the gearing is. under.load';wherebyl am enabledsto use standard pinions and gearshaving'parallel teeth, and then twist the pinion to meet the speeiiiedrequirements of the drivinginechanism. 1

1A furtheradvantage results fromfthe fact l that the .quill shaft willform a flexibleA conV neetionbetween the driving motoiand thedrivengear; ywhich 4w1ll-ass1st 1n absorbing .sudden shocktransmittedthrough the trein off'gears-drivenzby the motor. .Y

Having now fully described my invention.

whatvI claim and desire to protect byrLetters Patentisr..v i, A i

. l. The vcombination of a driving-pinion and a shaftsecured toeachother, one of said members being funder a' twisting strain when notunder load in a'direction to subA stantial'ly relieve the stra-in whendrivinglv the normal load calculated to "be driveii thereby; f y f p2. Adriving element havingtwosets of helical teeth .ona sleeve member,the-teeth of one set extending in an opposite direction to the teeth ofanother set, a quill Shaft extending through the sleeve member means forconnecting the sleeve member to the shaft in such al manner that bothsets of t teeth are between said connection, and means for coupling indriving relation one end of the shaft to a power transmitting member,

the shaft and sleeve being twisted relative to each other in a4 reversedirection to a twist caused by a load.

In testimony of which inventiom l have hereunto set my hand, at Trenton,J., on this 27th clay of July, 1921.

ARVD PETERSN.

